Thursday, October 7, 2010

Algebra PSLE 2010 P2 Q6

6.  Alan had 1.2 m of wire. He used some of it to make the figure shown below.


A pentagon is given, labelled from left to right and base: k cm, k cm, k cm, (k + 8)cm and (2 k - 5) cm.

(a) How much of the wire did Alan use to make the figure?
      Leave your answer in the simplest form in terms of k.

(b) If k=15, how much of the wire was not used to make the figure?


k  +  k  +  k  +  (k + 8)  +  (2 k - 5)  = (6 k  +  3) cm

a) Alan used (6 k + 3) cm.



6 x 15  +  3  =  93


120  -  93  =  27  cm

It was  27  cm.

2 comments:

  1. As appeared in PSLE 2010 exam:

    Alan had 1.2m of wire. He used some of it to make the figure shown below.

    Figure is a 5-side diagram labelled from left to right and base: k cm, k cm, k cm, (k+8)cm and (2k-5) cm.

    (a) How much of the wire did Alan use to make the figure?
    Leave your answer in the simplest form in terms of k.

    (b) If k=15, how much of the wire was not used to make the figure?

    PS: "not" in part (b) of this question was highlighted in bold.

    ReplyDelete